SOMEBODY slipped the ubiquitous second-banana Anthony Anderson a banana peel for his first starring vehicle, the vile “King’s Ransom.”

So embarrassing that New Line Cinema (which screened even “Son of the Mask”) dumped it into theaters without advance screenings, this laugh-free comedy improbably casts the rotund, pratfalling comic from films like “Kangaroo Jack” as Malcolm King, a self-made millionaire in Chicago.

King’s about to sell his company – whose principal product seems to be a marital aid called “Boneagra” – for $25 million, but doesn’t want to split the proceeds with the wife (Kellita Smith) he’s suing for divorce.

So King asks his dimwitted mistress (Regina Hall) to hire her equally stupid brother (Charlie Murphy) – a just-released convict Malcolm has never met – to kidnap him for ransom to avoid paying the ex.

The real King ends up being abducted instead by an even stupider redneck (Jay Mohr) whom he mistakes for the mistress’ brother – and held captive in the redneck’s grandmother’s basement.

There are even more improbable kidnap plots being hatched by the estranged wife and a group of King’s disgruntled employees.

You’ve probably guessed that this is the sort of movie where the characters’ collective IQ’s add up to less than zero.

None of this is remotely funny, despite screenwriter Wayne Conley’s resorting to virtually every known stereotype

about African-Americans and more crass references to menstruation and prison sex than have ever appeared in a movie rated PG-13.

There are some talented performers here, but you wouldn’t know it from newcomer Jeff Byrd’s lack of direction and pacing, which makes the 95-minute movie seem at least three times as long.

There were two other people in the audience at yesterday’s matinee at City Cinema’s East 86th St. theater; one fled the 313-seat auditorium for “A Lot Like Love” next door, while the other fell asleep.

Presumably, everyone else was at home enjoying actually entertaining kidnap comedies like “Ruthless People” or “The Ref” on DVD.